Define break times via time periods instead of plain times

aleksis/apps/chronos/migrations/0008_break_period.py

+# Generated by Django 3.0.4 on 2020-03-28 20:24
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('chronos', '0007_advanced_models_from_untis'),
+    ]
+
+    operations = [
+        migrations.RemoveIndex(
+            model_name='break',
+            name='chronos_bre_weekday_165338_idx',
+        ),
+        migrations.RemoveField(
+            model_name='break',
+            name='time_end',
+        ),
+        migrations.RemoveField(
+            model_name='break',
+            name='time_start',
+        ),
+        migrations.RemoveField(
+            model_name='break',
+            name='weekday',
+        ),
+        migrations.AddField(
+            model_name='break',
+            name='after_period',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='break_after', to='chronos.TimePeriod', verbose_name='Effective start of break'),
+        ),
+        migrations.AddField(
+            model_name='break',
+            name='before_period',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='break_before', to='chronos.TimePeriod', verbose_name='Effective end of break'),
+        ),
+        migrations.AddIndex(
+            model_name='break',
+            index=models.Index(fields=['after_period', 'before_period'], name='chronos_bre_period__925ac6_idx'),
+        ),
+    ]

aleksis/apps/chronos/models.py

@@ -663,13 +663,17 @@ class SupervisionArea(ExtensibleModel):
 class Break(ExtensibleModel):
     short_name = models.CharField(verbose_name=_("Short name"), max_length=10)
     name = models.CharField(verbose_name=_("Long name"), max_length=50)
-    weekday = models.PositiveSmallIntegerField(verbose_name=_("Week day"), choices=TimePeriod.WEEKDAY_CHOICES)
-    time_start = models.TimeField(verbose_name=_("Start time"))
-    time_end = models.TimeField(verbose_name=_("End time"))
+
+    after_period = models.ForeignKey("TimePeriod", on_delete=models.CASCADE,
+                                    verbose_name=_("Effective start of break"),
+                                    related_name="break_after", blank=True, null=True)
+    before_period = models.ForeignKey("TimePeriod", on_delete=models.CASCADE,
+                                  verbose_name=_("Effective end of break"),
+                                  related_name="break_before", blank=True, null=True)
 
     class Meta:
-        ordering = ["weekday", "time_start"]
-        indexes = [models.Index(fields=["weekday", "time_start", "time_end"])]
+        ordering = ["after_period"]
+        indexes = [models.Index(fields=["after_period", "before_period"])]
         verbose_name = _("Break")
         verbose_name_plural = _("Breaks")